A conventional revolving connector comprises the following elements:
(a) an outer case fixedly mounted to a steering column of a car; PA1 (b) an inner case mounted to and revolving with a steering wheel; and PA1 (c) a flat cable electrically connecting the outer case with the inner case. PA1 (a) a cylindrical outer case with a housing section on its outer wall and having an upper-end-opening; PA1 (b) an inner case mounted to and being rotatable relative to the outer case, and having a holder at its upper face; PA1 (c) a flexible flat cable coiled and accommodated in a space formed between an outer wall of a cylinder protruded to the center of either one of the outer case or the inner case and an inner wall of either one of the inner case or the outer case, and both ends of the flexible flat cable are fixed to the outer case and the inner case, respectively; PA1 (d) a fixed pin having its middle part held by the holder and its lower section inserted into the housing section, so that the rotation between both the cases is regulated, the pin having an engaging hole and a slit provided near the center of the inserted end, the slit communicating from the engaging hole to a lateral face, so that an elastic tip is formed at part of the lower section; and PA1 (e) a stopper pin extending through the engaging hole and the housing section. PA1 (a) a cylindrical outer case with a housing section on its outer wall and having an upper-endopening; PA1 (b) an inner case mounted to and being rotatable relative to the outer case, and having a holder at its upper face; PA1 (c) a flexible flat cable coiled and accommodated in a space formed between an outer wall of a cylinder protruded to the center of either one of the outer case or the inner case and an inner wall of either one of the inner case or the outer case, and both the ends of the cable are fixed to the outer case and the inner case, respectively; PA1 (d) a fixed pin having its middle part held by the holder and lower section inserted into the housing section, so that the rotation between both the cases is regulated, the pin having an engaging hole and a slit provided near the center of the inserted end, the slit communicating from the engaging hole to a lower end, so that an elastic tip divided into two sections is provided at part of the lower section; and PA1 (e) a stopper pin extending through the engaging hole and the housing section, and at least one side of the pin is wider than the slit's width. PA1 (a) an outer case with a housing section for accommodating an end of a fixed pin; PA1 (b) an inner case mounted to the outer case to be rotatable relative to the outer case, and having a holder for holding part of the fixed pin; PA1 (c) a stopper pin extending through the fixed pin and the housing section; PA1 (d) a flat cable coiled to be accommodated in a space formed between the outer case and inner case, both the ends of the cable are fixed to the outer case and the inner case, respectively.
This conventional revolving connector is described hereinafter with reference to FIGS. 10 and 11. FIG. 10 is a perspective view of the conventional revolving connector, and FIG. 11 is an exploded perspective view of the same connector.
In FIG. 11, cylindrical outer case 501 has openings at upper and lower ends. Inner case 502 is housed by outer case 501 so that inner case 502 is rotatable relatively to outer case 501. Cover 503 covers the lower opening of outer case 501 and is fixedly mounted thereto. Inner case 502 has a lid 521 covering the upper opening of outer case 501 as well as an inner cylinder 522 protruding downward from center.
An annular space (not shown) formed between the inner wall of outer case 501 and the outer wall of inner cylinder 522 accommodates a flat cable 504. Flat cable 504 is a flexible belt-like cable incorporating a plurality of conductive wires. The cable coils a plurality of turns and has terminals 541 and 542 at both ends, respectively. Terminal 541 is fixed to outer case 501 and terminal 542 to inner case 502. Terminal 542 is coupled to a first end of a lead wire 506 whose second end is coupled to a connector 505.
The revolving connector structured above is mounted to a steering device of a car in the following manner. Outer case 501 is fixedly mounted to a steering column of a car (not shown). The steering wheel (not shown) is inserted into cylinder 522 of inner case 502 so that the steering wheel is mounted to inner case 502. Terminal 541 is coupled to an electronic circuit of the steering column on the car body. Connector 505, on the other hand, is coupled to an electronic circuit disposed in the steering wheel, so that the steering wheel is electrically coupled to the steering column.
The revolving of the steering wheel causes inner case 502 to rotate. When inner case 502 rotates counter-clockwise, cable 504 is urged outwardly and loosely coiled. When inner case 502 rotates clockwise, cable 504 is urged inwardly and tightly coiled.
The steering wheel that rotates as discussed above is electrically coupled with the steering column fixed to the car body by the cable 504 having a fixed length. Therefore, the cable 504 needs to be at a neutral position where a number of turns inwardly balances with that of the number of turns outwardly when the revolving connector is mounted to the steering device of the car in the straight-ahead position, so that the counter-clockwise rotation balances with the clockwise rotations.
When the connector is assembled, cable 504 is set in the neutral position, then a U-shaped tab 571 laterally extending from a fixed pin (pin) 507 is engaged with a holder 523 upwardly protruded from a lid 521 of inner case 502 as shown in FIGS. 10 and 11. At the same time, a lower section 572 of pin 507 is inserted into a box-type housing 511 disposed on the outer wall of outer case 501. As a result, inner case 502 is temporarily held not to rotate relative to outer case 501. Under this condition, the revolving connector is warehoused or transported, then pin 507 is upwardly pulled out just before or after the revolving connector is mounted to the steering device, so that the characteristic discussed above of the conventional connector is obtained.
However, if pin 507 is pulled out by mistake and inner case 502 rotates to miss the neutral position in a warehouse, pin 507 can still be restored. Therefore, when mounting the revolving connector to the steering device, it is yet doubtful whether or not cable 504 is in the neutral position even pin 507 is in place.